We plan to continue our attempts to identify the pheromone from male mice using head space analysis of gas chromatography and mass spectroscopy. We also hope to develop a rapid assay of the pheromone using depletion of the hypothalamus of gonadotrophin releasing hormone. We will continue our studies of hermaphrodites by grafting side by side fetal ovaries and testes under the renal capsule. We will look for the development of functional ovotestes following grafting to an ovarian bursa. We will do these experiments in strains which do and do not exhibit natural hermaphrodism. One aim is to see if XO cells can produce sperm or XY eggs. Mouse blastocysts will be cultured through the implantation period and the medium examined for the presence of chorionic-like gonadotrophin. Attempts will be made to identify reproductive "cripples" and to breed these by artifical methods. We will study the role of membrane surface groups on artificial activation of mouse eggs.